PROJECT SUMMARY/ABSTRACT Socioeconomic health disparities in sleep and behavior problems are evident from early childhood. Young children in low-income families are at high risk of sleep and behavior problems, which often co-occur and predict long-term poor mental and physical health. These problems cause added strain in families that are already facing multiple poverty-related stressors, and family dysfunction in turn contributes to persistence and worsening of sleep and behavior problems. Engaging the family is essential to treating co-morbid sleep and behavior problems and preventing entrenched health disparities. Family interventions enhance child health outcomes; moreover, because child sleep, child behavior, and family functioning are intertwined, a successful intervention that addresses either sleep or behavior may lead to improvements both within and across domains. However, low-income families are often reluctant to seek or accept early intervention. Difficulty enrolling and retaining families undermines potential health benefits. Stigma associated with treating behavior problems also discourages families from accepting treatment. This project determines how best to overcome barriers to treatment in low-income families of children with co-morbid sleep and behavior problems. We compare how low-income families respond to two empirically-supported home visiting interventions, one treating sleep and the other treating behavior. Both are designed to address cultural, motivational, and logistical barriers to engagement. We also take the innovative approach of testing whether giving families a choice between a sleep or behavior intervention, so that the initial frame with which they enter the intervention relationship is one of self-determination, enhances family engagement and child outcomes. With a randomized, controlled trial design, we test effects of intervention (sleep vs. behavior), engagement, and family input (choice vs. assigned) on child symptoms and family functioning, and assess which intervention families most prefer, engage with, and value. We will enroll 500 low-income toddlers with co-morbid sleep and behavior problems, randomized to 4 home-visiting interventions: sleep, behavior, family choice (sleep or behavior), and an active control. At baseline and at 1, 5, and 9 months post- intervention, we will assess child sleep and behavior and family functioning. We will measure family preference, engagement, and perceived value of each intervention. Aim 1 is to examine effects of evidence- based sleep and behavior interventions in young low-income children with co-morbid sleep and behavior problems on child sleep and behavior and family functioning. Aim 2 is to determine whether parents prefer, engage with, and value a sleep or behavior intervention more. Aim 3 is to examine if giving families a choice of intervention results in higher engagement, higher perceived value and better family and child outcomes than assignment to intervention. By informing best practices for engaging low-income families to treat co-morbid sleep and behavior problems, results will be critical to reducing health disparities for children living in poverty.